Furnace for heating materials under sustained pressure



vFel). 16, 1937. P R. CHURCH ET AL l 2,070,983

FUBNACBFOR' HEATING MATERIALS UNDER SUSTAINED PRESSURE Filed April 2, 19536 2l Sheets-Sheet l ATTORNEY Feb. 16,` 1937. P. R. CHURCH ET AL 2,070,983

FURNAQE FOR HEATING MATERIALS UNDER' SUSTAINED PRESSURE File-d April?, 193e 2 sheets-sheet 2 ATTORNEY Patented Feb. 16, 1937 FURNACE FOR HEATING MATERIALS UNDER SUSTAINED PRESSURE Peter 1t. Church, Steubenville, hio, and Henri C. Rateau, Weirton, W. Va.

Application April 2, 1936, Serial No. 72,346

'i claims. (o1. 26a-4a) This invention relates broadly to furnaces, and more specifically to furnaces for heating or soaking steel ingots preparatory to introduction of the ingots to the blooming mill in the process of manufacturing steel sheets and the like.

The primary object of the invention is to provide a furnace of the character described requiring a minimum of floor space in which the ingots are heated under a continuous sustained pressure in such a manner as to create a uniform heating and soaking condition without permitting the impingement of fuel combustion tc attack any portion of the metal during the heating and soaking period.

Another and important object of the invention is to afford rie-circulation rf waste heat and gases in the furnace in suchA a manner that they can be readily induced to mix with the delivery of fuels to the furnace to facilitate efficient combustion. Thus, while the furnace affords a better quality of heating it also can be economically operated by reason of utilizing and re-introducing into the furnace for purposes of complete combustion fuels and gases which would otherwise be wasted.

Another object of the invention is to provide a furnace structure which can be economically constructed and operated, and one in which the cost of upkeep is comparatively small. Other objects and advantages of the invention will appear from the following detailed description taken in connection with the accompanying illustrative drawings, in which- Figure 1 is anisometric view of the furnace, portions thereof being cut away and shown in section to illustrate interior construction;

Figure 2 is a fragmentary horizontal sectional view taken on line 2--2, Fig. l;

Figure 3 is a top plan view of the furnace with the cover and fans removed;

Figure is a vertical sectional view taken on line d--lk Fig. 3; and- Figure 5 is a fragmentary vertical sectional view of the bottom portion of the furnace taken on line 5 5, Fig. 3.

Referring to said drawings, the reference numeral 2 designates a concrete base supporting the furnace structure, the latter consisting of side walls and end walls 3 and d, respectively. Each of said walls is preferably formed to an appropriate thickness of brick, the outer portion of the wall consisting of common clay or building brick while l the inner portion or liningI consists of a suitable refractory brick. Located intermediate the common clay brick and the refractory brick lining is a thickness of an appropriate insulating material 5, the same obviously being provided to reduce the dissipation of heat through the furnace walls. A rectangular inner wall 6 is provided at a spaced distance from the lining of the outer walls 3 and Il to provide an air space or passage l therebetween, the wall 6 being maintained rigid by a plurality of staggered tie bricks 8 anchored to the respective wall structures. A plurality of ports l l arranged in staggered relation and to a predetermined height in the wall 6 aord means of communication from the interior heating chamber of the furnace to theyertical passages l.

The sub-iloor Il is preferably made of refractory brick with a layer of insulation l2 intermediate predetermined courses of brick, the subfloor being recessed, as shown at I3, to provide means for accommodating the removable ingot supporting oor which will now be described.

A series of spaced parallel ingot supporting ribs It extend longitudinally of the furnace bottom, said ribs being made of a substance, as metal having high heat resisting properties. Heat resisting concrete l5, reinforced by rods I6, is provided in the spaces intermediate each rib lt, the concrete being of such depth as to permit the upper portion of each rib to protrude upward above the level of the concrete upon which the ingots il are supported in spaced relation, one such ingot being depicted in Figs. 1 and 3 of the drawings. Transverse braces It, also made of high heat resisting metal, underlie the ribs M at a spaced distance from the opposite ends of the latter and arev embedded in the concrete l5 and, additionally, have their lower edges snugly received within registering transverse grooves provided in the sub-floor ll. A series of spaced notches I9 cut out of the transverse braces t8 receive the horizontal ribs I4, as shown in Fig. 4, for affording rigidity to the latter. From the above description it will be observed that the ingot supporting oor is capable of being removable as a unit from the furnace for repairs or replacement. Otherwise expressed, the ribs 4 and intermediate concrete l5 overlie the braces I 8` and all of said elements can be removed as a unit `merely by elevating the two braces I8. Apertures 20 are provided in each of said braces to accommodate hooks of a lifting crane to facilitate removal.

Flues 2l are provided in the end walls 4 adjacent the bottom thereof and on substantially the same plane as the surface of the concrete I5. Each of said ilues 2l is `in vertical alignment with the passage l and is isolatedfrom the latter by a bafile wall 22. Openings 23 are provided in the end walls of the walls 6 at the floor level of the furnace, the openings being arranged sov that one thereof is provided between each two ingot supporting ribs |4. Thus, communication between the flues 2| and the heating chamber is 1 ney or stack (not shown) for carrying olf prod'- ucts of combustion when the dempers 25 'are Open.

Another tube 26 extends horizontally through y each of the end walls 4 adjacent the bottom and at a spaced distance from the four corners of the furnace and has its inner end in open communication with the iiue 2|, each of said tubes being equipped with a damper 2l. The outer end of each tube 26 protruding exteriorly of the end walls of the furnace is turned upwardly and is connected with a fan 28, which latter is, in turn, connected to a smallertube 29 penetrating the furnace end walls and opening into the heating chamber in alignment with the burner opening 30 of the end walls of the inner Wall 5.

Similar burner openings 3|! are provided inv each of the side and end Walls of the inner wall 6 adjacent the upper end thereof, the same being intended to register with burners 3| entering through the outer wall and supplied withy fuel, as gas, oil, powdered coal, or the like. While a burner 3| and burner opening 30 is herein shown in relation with each side and end wall, it will be understood that the number and location may be varied. 'Ihe burner depicted in section in Fig. 1 of the drawings is adapted to utilize air and gas as fuel, the air being supplied under a. predetermined velocity through the outer tube 3|, while the gas is supplied through the inner and smaller tube 32.

l A number of clean-out openings 33 are provided in the end of the furnace, these openings preferably being located in register with the ue openings 2| and affording means whereby the furnace iioor may be appropriately cleaned of undesirable foreign matter from the exterior at intervals by the insertion of an appropriate implement. Removable closures, as 34, seal said clean-out openings 33when the latter are not being utilized.

A removable cover 35 closes the top of the furnace, the same being lined with a heat resisting material. Peep holes (not shown) may, if so desired, be provided in said cover 35 through which the interior of the furnace may be viewed during operation, thepeep holes being closed when not in use.

In operation, a plurality of ingots, as I1, are placed in the furnace through the opening in the top and are arranged in spaced vertical position with their lower ends resting upon the ribs Il, after which the cover 35 is positioned for sealing the heating chamber from the atmosphere. -Fuel is introduced into the heating chamber through the burners 3| and, when ignited, the products of combustion raise the temperature and pressure of the heating chamber to the desired point, the fuel thereafter being permitted to complete its combustion under a continuous and sustained x-essuie condition.- Waste heat and gases, due to the sustain ed pressure maintained in the heating chamber, are permitted tc course through the ports It into the vertical passage l from whence they are forced or drawn. toward the burner openings Bilanci are permitted and induced to commingle with the fuel delivered through the burners 3| after which substantially complete combustion and utilization of the otherwise waste heat and gases takes place within the heating chamber. I

Since the heating chamber is under predetermined sustained pressure, varying pressure or temperature zones or pockets are eliminated, and, consequently, the temperature thereof is maintained uniform throughout and the ingots are, therefore, uniformly heated. Moreover, continuous circulation of the products of combustion is experienced permitting the lower portions of the ingots to be heated equally with the top portions. Since the ingots are supported on the upstanding spaced ribs Ill, the heating temperature has access to the very bottom of each ingot inasmuch as circulation thereunder is afforded.

The meeting of the air and gas at the burner, as Well as the pressure maintained in the heating chamber, acts to reduce the velocity of the delivered fuel so that the objectionable rashness of the heat so injurious to metals is materially reduced, if not entirely eliminated. Furthermore, impingement of fuel combustion on the ingots is further eliminated by preferably placing the burners 3| at a point above the plane of the ingots, although, as hereinbefore stated, the location of the burners may be varied. Experience also teaches that for quality heating the ingots should not be placed in direct line with the line of re of the burners.

Waste products of combustion may be removed from the furnace by opening' the dampers 25 thereby permitting the waste products to course along the floor between the ribs lt and make their exit from the heating chamber to the flues 2| through the openings 23. From the flues 2| the waste products'are carried to the chimney through the conductors 24. This precise method may also ybe resorted to when it is desired to decrease or otherwise control the pressure maintained within. the heating chamber.'

On the other hand, it may be found advantageous during the operation of the furnace to close the dampers 25; open the dampers 21 and operate the fans 28 to re-introduce the heated waste products of combustion into the furnace under pressure to mix with the delivered fuel in order to securemaximum combustion. Then, too, as is well known in the art, thev furnace may be even more eiciently and economically cperated by suitably preheating the fuels prior to introduction into the furnace.

Moreover, the intensity, velocity, volume and direction of the fuel firing burners may be so regulated and positioned as to control the thickness of the scale formed on the ingots during treatment, it being desirable in some cases to have heavier layers of scale than in other inf stances.

While we have herein described and illustrated a preferred embodiment of the invention, and dea,ovo,ess

heating as used herein and hereafter. Hence, it is not intended to be limited to the precise details set forth, and we shall consider ourselves at liberty to make such changes and alterations as fairly fall rwithin the spirit and scope of the appended claims.

What is claimed is- 1. In a furnace for heating materials undersustained pressure consisting of outer side and end walls and a removable' closure for the charging opening, an inner heat chamber dening wall spaced away from said outer side and end walls to provide a passageway therebetween, a burner penetrating the outer wall and in register with an opening in the inner heat chamber dening wall, a plurality of ports provided in the heat chamber wall affording an avenue for the passage of products of combustion from the heating chamber tosaid rst mentioned passagewayand thence to said burner opening from whence said products of combustion may be re-introduced to the heating chamber through the` burner open- (l inglin the heat chamber wall along with the fue 2. In a furnace for heating materials under sustained pressure, an outer wall, a closure, an inner wall dening a heating chamber, said inner wall being spaced away from said outer wall to provide a passageway therebetween, 'a burner penetrating the outer wall and in register with an opening in the inner heat chamber defining wall, a plurality of ports provided in the lower portion of the heat chamber wall affording an avenue for the passage of products of combustion from the heating chamber to the passageway and thence to said burner opening from whence said products of combustion may be reintroduced to the heating chamber through the burner opening in the heat chamber wall along with the fuel, and a ue beneath and isolated from said passageway and communicating with the heating chamber and leadingexteriorly of the furnace whereby products of combustion may be emitted from the furnace.

3. In a furnace for heating materials under sustained pressure, outer side and end walls, a removable closure for the charging opening, an inner heat chamber dening wall spaced away from said outer side and end walls, a burner penetrating the outer wall and in register with an opening in the inner heat chamber defining wall, said opening communicating with the heating chamber and the space between the heating chamber wall and the outer walls, a plurality of ports provided in the lower portion of the heat chamber wall and extending throughout the `horizontal extent thereof affording avenues for the passage of products of combustion from the heating chamber to the space between the heating chamber wall and the outer walls from whence they may be conducted to said burner opening for reintroduction to the heating chamber through said opening along with the fuel introduced from the burner.V

4'. In a furnace for heating materials under sustained pressure consisting of outer side and end walls and a removable closure for the charging opening, an inner heat chamber defined by side and end walls spaced away from said outer walls to provide a passageway between the inner and outer walls encompassing said heat chamber, means for introducing fuel to said heating chamber through an opening in the heating chamber wall, and avenues of communication between said heating chamber and the encompassing passageway provided in said heating chamber walls affording avenues for the passage of products of combustion from the heating chamber to said passageway and thence to said burner opening from whence said products of combustion may be re-introduced to the heating chamber through the burner opening in the heat chamber wall along with the fuel.

5. In a furnace for heating materials consisting of outer walls and inner heat chamber dening walls spaced away from said outer walls to provide a passageway therebetween, a burner penetrating the outer wall and in register with an opening in the inner heat chamber defining wall, ports provided in the heat chamber walls affording an avenue for the passage of products of combustion from the heating chamber to said iirst mentioned passageway and thence to said burner opening from whence said products of combustion may be re-introduced to the heating chamber through the burner opening in the heat chamber wall along with the fuel.

6. In a furnace for heating materials, an outer wall, oppositely disposed walls confined within and spaced away from said outer wall to define a heating chamber and providing a passageway between said heating chamber walls and said outer wall, means for introducing fuel to said heating chamber through an opening communicating with the heating chamber and said passageway, and avenues of communication between said heating chamber and the passageway provided in the heating chamber walls whereby products of combustion from said heating chamber may enter said passageway through opposite heat chamber walls and course through said passageway to said fuel opening from whence they may be re-introduced to the heating chamber through said fuel opening along with the fuel.

'1. In a furnace for heating materials, an outer wall, oppositely disposed walls conflned within and spaced away from said outer wall to denne a heating chamber and providing a passageway between said heating chamber waJls and said outer wall, means for introducing fuel to said heating chamber through an opening communicating with the heating chamber and said passageway, and an avenue of communication between said heating chamber and the passageway provided in said heating chamber wall whereby products of combustion may enter said passageway from the heating chamber and be conducted to said fuel opening while confined within the outer wall whence they may be re-introduced to said heating chamber through said fuel opening along with the fuel.

PETER R. CHURCH. HENRI C. BATEAU. 

